Abstract

Objective To study the association of self-reported physical activity level with prognosis in a cohort of patients with coronary heart
disease (CHD), with a special focus on the dose–response relationship with different levels of physical activity.

Methods Data were drawn from a prospective cohort of 1038 subjects with stable CHD in which frequency of strenuous leisure time physical
activity was assessed repeatedly over 10 years of follow-up. Multiple Cox proportional hazards regression models were used
to assess the association of physical activity level with different outcomes of prognosis (major cardiovascular events, cardiovascular
mortality, all-cause mortality), with different sets of adjustments for potential confounders and taking into account time-dependence
of frequency of physical activity.

Results A decline in engagement in physical activity over follow-up was observed. For all outcomes, the highest hazards were consistently
found in the least active patient group, with a roughly twofold risk for major cardiovascular events and a roughly fourfold
risk for both cardiovascular and all-cause mortality in comparison to the reference group of moderately frequent active patients.
Furthermore, when taking time-dependence of physical activity into account, our data indicated reverse J-shaped associations
of physical activity level with cardiovascular mortality, with the most frequently active patients also having increased hazards
(2.36, 95% CI 1.05 to 5.34).

Conclusions This study substantiated previous findings on the increased risks for adverse outcomes in physically inactive CHD patients.
In addition, we also found evidence of increased cardiovascular mortality in patients with daily strenuous physical activity,
which warrants further investigation.